Laboratory accelerated weathering test chambers and test services are described in the art. For example, three different models of accelerated weathering test devices are available from Q-panel Lab Products, Cleveland, Ohio under the trade designations “Model QUV/se”, “Model QUV/spray” and “Model QUV/basic”.
According to the Q-panel website (www.q-panel.com on Jul. 28, 2004), the “QUV Accelerated Weathering Tester” reproduces the damage caused by sunlight, rain, and dew. The QUV tests material by exposing them to alternating cycles of light and moisture at controlled, elevated temperatures. The QUV simulates the effect of sunlight with fluorescent ultraviolet (UV) lamps. It simulates dew and rain with condensing humidity and water sprays. Exposure conditions can be varied to simulate various end-use environments. Although UV is only about 5% of sunlight, it is responsible for most of the photochemical damage to durable materials outdoors. To simulate the damage caused by sunlight it is not necessary to produce the entire spectrum of sunlight. It is only necessary to simulate this short wave UV. The UVA-340 lamp gives an excellent simulation of sunlight in the region from 365 nm down to the solar cut-off of 295 nm. The UVA-340 produces only those UV wavelengths found in sunlight. In a few days or weeks, the QUV reproduces the damage that occurs over months or years outdoors. Types of damage include color change, gloss loss, chalking, cracking, hazing embrittlement, and strength loss. QUV test data can help in the selection of new materials, the improvements of existing material or the evaluation of changes in formulations.”
Another manufacturer of commercially available laboratory weathering test chambers is Atlas Material Testing Solutions, Chicago, Ill. a supplier of xenon arc instruments, fluorescent devices, carbon arc devices and metal halide systems. According to their website (www.atlas-mts.com on Jul. 28, 2004), “Tests using fluorescent lamps are useful for relative rank comparisons between materials under specific conditions, but the comparison to service lifetime performances or correlation to outdoor exposures may not be valid.”